Cruise Control and Shift in low

[bglasvegas]

During my dealership delivery training I ask the question if they knew if I could coast down hill in low with the cruise control set to the speed limit and maintain the speed set without touching the breaks. They did not know since maybe cruise costing in low would be seen as applying the brakes and kick you out of cruise.

Well I had to test that, so I took a trip up to Mount Charleston and Lee Canyon ski resort at 8000 plus feet. I used MM on the way up as I had to test the engine. It worked as expected and I consumed 2.2 gals of gas in cruise at 55mph on the way up. (5000+ foot climb) I did not log the miles, but the car reported 35.5 mpg in CS. On the trip down I set the cruise at 45 mph and in Low all the way down. My Volt maintained 45 all the way and regen added 27 miles to the battery range till I came to HyWay 95 and the trip back to Vegas at 70mph all on battery. It was so great to see the battery range going up as I was heading downhill on the long run.

Bottom line: the volt will hold speed on the down hill and stay in cruise till you hit the break pedal ! !!!

Has this topic been discussed on this forum before? I did a search and came up empty.

Bob
C8329, White Diamond with light interior. And I do love the looks of this interior.

[Steverino]

You may be the first to test this, bglasvegas. Nothing beats a real world experience. Regrettably, not much opportunity to test driving down a mountain in cruise with L around Chicago, hahaha. Thanks for sharing!

[tboult]

It has been discussed before, but the search function is pretty broken so its probably okay to revisit things when there are many new owners. If you tried and could not find it, maybe they cannot either.

I know I posted about it when I did my trip down loveland pass it was very effective. My trip includine continuing on I70 in CO, and I significantly extended my range. (75M on a single charge) even with CC holding my speed down to 65mp or 70mph.

[WVhybrid]

I found cruise control to do a good job either uphill or downhill. I've driven across the mountains on I-64 to the Virginia border from Beckley, WV and across I-68 from Morgantown,WV to Cumberland, MD. I've never seen the speed vary by more than 1 unit (mph) either up or down. Sometimes the cruise control will overshoot by 1 unit when transitioning from one angle to another, say at the crest of a hill.

It would be interesting to know how the cruise control is tuned. I assume that it is some sort of adaptive control that changes the gain and reset as speed and engine load change.

WVhybrid

[Robinpdx]

During my dealership delivery training I ask the question if they knew if I could coast down hill in low with the cruise control set to the speed limit and maintain the speed set without touching the breaks. They did not know since maybe cruise costing in low would be seen as applying the brakes and kick you out of cruise.

Well I had to test that, so I took a trip up to Mount Charleston and Lee Canyon ski resort at 8000 plus feet. I used MM on the way up as I had to test the engine. It worked as expected and I consumed 2.2 gals of gas in cruise at 55mph on the way up. (5000+ foot climb) I did not log the miles, but the car reported 35.5 mpg in CS. On the trip down I set the cruise at 45 mph and in Low all the way down. My Volt maintained 45 all the way and regen added 27 miles to the battery range till I came to HyWay 95 and the trip back to Vegas at 70mph all on battery. It was so great to see the battery range going up as I was heading downhill on the long run.

Bottom line: the volt will hold speed on the down hill and stay in cruise till you hit the break pedal ! !!!

Has this topic been discussed on this forum before? I did a search and came up empty.

Bob
C8329, White Diamond with light interior. And I do love the looks of this interior.

Great information as I live in mountainous area too ( Western Oregon). I don't fully understand though, if you drove on MM to the top, then didn't you already have 17 miles of battery left over for your trip down, so gained only 10 (not that that is bad mind you). My question though is if the electric motor is working harder to drive the car in low range, wouldn't it have used more battery? I would wonder what your results are doing the exact same trip but in D on the way down. I know for me to coast down a hill in low, it has to be one heck of a steep hill.

[Rusty]

My question though is if the electric motor is working harder to drive the car in low range, wouldn't it have used more battery?

I'm not sure you understand the difference between D and L. They don't change any gearing in the Volt, and the motor doesn't have to work any differently in L versus D to drive the car, as long as you have your foot on the accelerator (enough).

All L does is map some regen into the very first bits of the accelerator pedal play, so lifting your foot off the accelerator causes increased regeneration compared to driving in D. If your traveling on level ground at 90 MPH in L, the motor is working exactly as hard as it would be if you were driving the car at 90 MPH in D.

As for coasting down hill, if you've got the cruise control on in L the car will engage regeneration to keep you from going over the set speed. It won't (at least my '11 won't) if you're in D, and the car will coast down hill faster than the set point on a steep enough hill.

[bglasvegas]

Nope; I added 27 to the 14 left after returning to normal mode. Rusty is correct. Driving in D down hill in cruise, the car will not hold set speed. But in L, all is good!

[pdt]

Thanks for the info, it's really good to know that.

[silvercorvette]

I like to have control of my car and try to avoid Cruise control because I can anticipate situations where I need to speed up or slow down and react faster than the cruise control. I have to admit the I would love to have had the optional radar controlled cruise control on my Lexus. It knows when you are getting too close to another car and backs off. C/C is great because it allows you to relax your right leg on a long drive but if you don't pay close attention it can be a hazard.

I don't know it this is true or and urban legend and it could be true because there are no limits to people stupidity. But the story is that someone in a new motor home wanted to make so coffee so the flipped on the C/C and walked back to brew coffee with no one behind the wheel.

There was even a scene in a movie that had the motor home coffee incident

I checked ut snopes, here is a link

http://www.snopes.com/autos/techno/cruise.asp

[voltage692]

Since when did cruise control also control the steering of the vehicle???

That's the dumbest myth I have heard in a long time, and I wouldn't want to be the one to perpetuate it on forums.

I like to have control of my car and try to avoid Cruise control because I can anticipate situations where I need to speed up or slow down and react faster than the cruise control. I have to admit the I would love to have had the optional radar controlled cruise control on my Lexus. It knows when you are getting too close to another car and backs off. C/C is great because it allows you to relax your right leg on a long drive but if you don't pay close attention it can be a hazard.

I don't know it this is true or and urban legend and it could be true because there are no limits to people stupidity. But the story is that someone in a new motor home wanted to make so coffee so the flipped on the C/C and walked back to brew coffee with no one behind the wheel.

There was even a scene in a movie that had the motor home coffee incident

I checked ut snopes, here is a link

http://www.snopes.com/autos/techno/cruise.asp